In transmission mode, photoconversion is relative to the creation of photons by an electronic device subject to a current or voltage, or, in receiving mode, to the modification of electrical properties in the presence of photons.
In particular, two types of receiving device are often used: photoelectric devices in which a photon modifies resistivity and photovoltaic devices in which photon reception brings about the creation of a current by the device.
The first type of device is useful for forming light-detection sensors or for adapting a process to a given luminosity.
The second type of device can be used either as a light-detection sensor or as a current or voltage generator, for example, to supply current and/or voltage to an electrical network or to another electronic device. Both types of device fall globally into the field of “intelligent” material devices, which interact with external stimuli and have applications in the fields of safety and threshold detection, among others.
Materials known to the state of the art for forming photoelectric devices are generally semiconductor materials. They are, for example, monocrystalline materials such as silicon or gallium arsenide, or polycrystalline silicon or other amorphous materials. To manipulate these materials and fabricate devices, it is generally necessary to employ microelectronic techniques that are costly and difficult to implement.
Other materials exist, such as colorant-based materials. However, this solution uses rare materials such as ruthenium, for example, and requires a nanoparticle foam of titanium dioxide to obtain good yields. Moreover, it is necessary to maintain the colorant in solution in a liquid, which can necessitate the resolution of sealing problems and involves taking precautions in the event of freezing of the liquid solution.
Another known solution is the use of organic materials. These materials are comparatively ineffective compared to other solutions and entail the risk of polymer recrystallization as well as degradation risks when there are variations in temperature.
At present, none of the known solutions is completely satisfactory. Devices having better energy yield or better sensitivity or low design cost are sought after. The world of industry, therefore, is searching for new ways of producing such devices.